This paper proposes a comprehensive novel multi-terminal HVDC protection scheme based on artificial neural network (ANN) and high frequency components detected from fault current signals only. The method is shown to accurately detect, classify and locate overhead line faults. Unlike existing travelling wave based methods which must capture the initial wavefront and require high sampling rates, the new approach is more robust since it gives accurate fault detection and fault location over a range of windowed post-fault signals. Furthermore, the proposed method is fault resistance independent meaning even a very high fault impedance has no effect on accurate fault location. A three-terminal VSC-HVDC system is modelled in PSCAD/EMTDC, which is used for obtaining the fault current data for transmission line terminals. The method is verified by studying different cases with a range of fault resistances in various fault locations, and in addition, external faults. The results show that the proposed method gives fast (<5 ms) and reliable (100%) fault detection and classification and accurate location (<1.16%) for DC line faults

The accelerating market penetration of electric vehicles (EVs) raises important questions for both industry and academia: how to deal with potentially millions of retired batteries (RBs) from EVs, and how to extend the potential value of these batteries after they are retired. It is therefore critical to deepen our understanding of the comprehensive performance of RBs in appropriate applications, such as stationary energy storage with less-demanding on power capacity. The following literature review evaluates the opportunity of the emerging RB market in detail. Meanwhile, various specifically technical issues and solutions for battery reuse are compiled, including aging knee, life predicting, and inconsistency controlling. Furthermore, the risks and benefits of battery reuse are highlighted referring to transportation electrification and entire industrial chain. Also, current policy shortcomings and uncertainties are outlined, and policy recommendations are provided for relevant participants. Six typical application scenarios are selected, and high-value business models for battery reuse are explored from different techno-economic aspects. Insights from this review indicate that as the entire recycling chain is completed, battery reuse will be essential to the future energy market and will play an important role in the future development of low-carbon energy.